The Biology of MindThe Biology of Mind

Nervous SystemNervous System

• Relays electrical signals through the body, Relays electrical signals through the body, directs behavior and movement and controls directs behavior and movement and controls physiological processes physiological processes

• The nervous system can be broken down into The nervous system can be broken down into two parts:two parts:

o Central nervous system (CNS)Central nervous system (CNS)• Brain and spinal cordBrain and spinal cord

o Peripheral nervous system (PNS)Peripheral nervous system (PNS)

• Touch, taste, smell nerve cellsTouch, taste, smell nerve cells

Peripheral Nervous SystemPeripheral Nervous System

• Somatic Nervous SystemSomatic Nervous Systemo Branch of the PNS that transmits sensory Branch of the PNS that transmits sensory

information to the CNS and carries out its motor information to the CNS and carries out its motor commandscommands

o Afferent (sensory) neurons carry messages Afferent (sensory) neurons carry messages toto the the CNSCNS

o Efferent (motor) neurons carry messages Efferent (motor) neurons carry messages fromfrom the the CNS to the muscles of the bodyCNS to the muscles of the body

• Autonomic Nervous SystemAutonomic Nervous Systemo Branch of the PNS that carries messages between Branch of the PNS that carries messages between

the CNS and internal organsthe CNS and internal organs (digestion, glucose (digestion, glucose release, respiration) release, respiration)

1)1) Sympathetic nervous systemSympathetic nervous system

2)2) Parasympathetic nervous systemParasympathetic nervous system

1)1) Sympathetic nervous systemSympathetic nervous system Activates body’s “fight or flight” responsesActivates body’s “fight or flight” responses Increased heart rate, dilated pupils, sweating, Increased heart rate, dilated pupils, sweating,

dry mouth, stops digestion dry mouth, stops digestion

22) ) Parasympathetic nervous systemParasympathetic nervous system Supports more mundane bodily functionsSupports more mundane bodily functions Regulates blood sugar levels, saliva Regulates blood sugar levels, saliva

production, waste managementproduction, waste management

Autonomic Nervous SystemAutonomic Nervous System

Neural CommunicationNeural Communication

• NeuronsNeuronso Nerve cells found throughout the nervous Nerve cells found throughout the nervous

system system o Specialize in electrical and chemical Specialize in electrical and chemical

communicationcommunication

• NeurotransmittersNeurotransmitters o Chemical messengers that “transmit” Chemical messengers that “transmit”

electrons/information across synaptic gaps of electrons/information across synaptic gaps of neurons then caught by receptor proteins on neurons then caught by receptor proteins on the next neuron/nerve cellthe next neuron/nerve cell

The BrainThe Brain

SECTION OF BRAIN FUNCTION

Brain stem Receives information from the brain to control basic functions (heart

rate, respiration, blood pressure, swallowing, coughing, sneezing, vomiting, etc)

Thalamus Main information pathway between the brain and the spinal cord (like

the phone jack in the back of your computer)

Hypothalamus Control center for our body's homeostasis (regulates body temperature,

appetite, thirst for water, desire for salt, etc).

Cerebellum Keeps movements smooth and coordinated, helps maintain posture,

muscle tone, and equilibrium/balance

Cerebrum Intellect, speech, and memory

The BrainThe Brain

• Occipital LobeOccipital Lobeo Specialized for vision Specialized for vision

• Parietal LobeParietal Lobeo Sense of touch, spatial orientation, awarenessSense of touch, spatial orientation, awareness

• Temporal LobeTemporal Lobeo Hearing and language functions, visual pattern Hearing and language functions, visual pattern

recognitionrecognition

• Frontal lobeFrontal lobeo Movement, attention, planning, abstract Movement, attention, planning, abstract

thinkingthinking

The BrainThe Brain• Hemispheric specializationHemispheric specialization

o Each hemisphere control the opposite side of Each hemisphere control the opposite side of the bodythe body

o Right hemisphere = excels at spatial functionRight hemisphere = excels at spatial functiono Left hemisphere = speaking, language, mathLeft hemisphere = speaking, language, math

Limbic SystemLimbic System

• Area of the brain that involves emotion and Area of the brain that involves emotion and motivationmotivation

• Fully developed only in mammalsFully developed only in mammals• Consists of:Consists of:

• Amygdala Amygdala - emotional processes; attaches - emotional processes; attaches emotional emotional significance to significance to emotional events)emotional events)

• Hypothalamus Hypothalamus - regulates the autonomic - regulates the autonomic system system

• Hippocampus Hippocampus - memory, storing new - memory, storing new informationinformation

Endocrine SystemEndocrine System

• Collection of glands throughout the body that Collection of glands throughout the body that secrete chemicals (called hormones) directly into secrete chemicals (called hormones) directly into bloodstreambloodstream

• Guide metabolism, growth, and sexual Guide metabolism, growth, and sexual developmentdevelopment

• Hypothalamus links brain to pituitary gland which Hypothalamus links brain to pituitary gland which in turn activates other glands in endocrine systemin turn activates other glands in endocrine system

• Hormones such as adrenaline/noradrenalin trigger Hormones such as adrenaline/noradrenalin trigger physiological arousal (re: danger) physiological arousal (re: danger)

Hormones (adrenaline) are similar to neurotransmitters Hormones (adrenaline) are similar to neurotransmitters (norepinephrine) related to anxiety/fear(norepinephrine) related to anxiety/fear

Endocrine system uses hormone secretion to “broadcast” Endocrine system uses hormone secretion to “broadcast” via bloodstream (highway) vs. neurotransmitters which via bloodstream (highway) vs. neurotransmitters which “talk” to one neuron then another in rapid succession“talk” to one neuron then another in rapid succession

Brain TechnologyBrain Technology• ESB ESB

o Electronic stimulation of the brain (in animals)Electronic stimulation of the brain (in animals)o Electrode planted in an area of the brain to Electrode planted in an area of the brain to

stimulate that region (IV) to determine any stimulate that region (IV) to determine any changes in behavior (DV)changes in behavior (DV)

• EEG EEG o Used to study electrical activity of the brain Used to study electrical activity of the brain o Electrodes placed on scalp and brain becomes Electrodes placed on scalp and brain becomes

“mapped” as areas “light up”“mapped” as areas “light up”

• CAT CAT o Computerized axial tomography (MRI, PET)Computerized axial tomography (MRI, PET)o Assembles three dimensional picture of brain Assembles three dimensional picture of brain

from x-raysfrom x-rayso Detection of abnormalities of mass (tumors)Detection of abnormalities of mass (tumors)

Brain DisordersBrain Disorders

• DeliriumDeliriumo Disturbance of brain metabolic functionDisturbance of brain metabolic function

o Symptoms include disorientation, Symptoms include disorientation, hallucinating, disturbed sleep, incoherent hallucinating, disturbed sleep, incoherent speech speech

o Treatment entails removing the underlying Treatment entails removing the underlying cause, detoxification, rehydration, etc.cause, detoxification, rehydration, etc.

o Common in dying patients as organs shut Common in dying patients as organs shut downdown

• DementiaDementiao Loss of mental capacity in adulthood Loss of mental capacity in adulthood

o ““Senile dementia” = 10 - 20% of people Senile dementia” = 10 - 20% of people > 65 years> 65 years

o Causes include Alzheimer’s disease, Causes include Alzheimer’s disease, vascular problems, alcoholism, paresis vascular problems, alcoholism, paresis

o Symptoms include poor awareness of Symptoms include poor awareness of time, depression, paranoia, parts of the time, depression, paranoia, parts of the brain maintaining everyday functions brain maintaining everyday functions shut down (incontinence)shut down (incontinence)

Brain DisordersBrain Disorders

• Alzheimer’s DiseaseAlzheimer’s Diseaseo Progressive and incurableProgressive and incurable

o Cause by tangled neurons that disrupt Cause by tangled neurons that disrupt functioning of the cortexfunctioning of the cortex

o Low level of neurotransmitters (ACH) Low level of neurotransmitters (ACH) which plays a role in memory functionwhich plays a role in memory function

o Neurons in the brain are destroyed, Neurons in the brain are destroyed, severely impairing memory, reasoning, severely impairing memory, reasoning, perception, language, behavior, etc.perception, language, behavior, etc.

o Genetic causes (chromosome 21)?Genetic causes (chromosome 21)?

Brain DisordersBrain Disorders